Thompson held off Serwa in the four-rider big final as the Canadians easily finished first and second.

Their medal path was made easier after 37-year-old Ophelie David of France -- bidding to become the oldest woman to win a solo event at the Winter Olympics -- fell.

Sweden's Anna Holmlund earned the bronze behind the silver medalist Serwa, who was a front-runner much of the day after posting the top time in the seeding round and winning her 1/8 final and quarterfinal races.

She was at risk of not making it out of the semifinals before reigning world champion Fanny Smith, leading the race, lost speed on a bump near the end of the course to open the door.

Sweden's Sandra Naeslund, 17, won the small final to take fifth place ahead of Austria's Katrin Ofner, Australia's Katya Crema and Smith.

Thompson, who leads the World Cup standings, finished first in her 1/8 final and was fighting for a top-two spot in her quarterfinal when Switzerland's Sanna Luedi fell down the stretch. Thompson won the heat and then beat David in the second semifinal.

Another Canadian, Georgia Simmerling, finished first in her 1/8 final but fell in the quarterfinals and was knocked out of medal contention.

Thompson followed in the tracks of Ashleigh McIvor, who won gold for Canada on home soil at the Vancouver Olympics but has since retired.

Canada's 1-2 finish followed a French medal sweep of the men's event Thursday, led by winner Jean Frederic Chapuis.

The only previous Olympic medalist in the women's field, Marion Josserand of France, was knocked out in the 1/8 finals.

Australia's Sami Kennedy-Sim, who suffered a stroke last April and returned to competition only months later, crashed after losing control around a turn in her 1/8 final and failed to advance.

Germany's Anna Woerner and Chile's Stephanie Joffroy were both taken off the hill on stretchers after separate quarterfinal crashes, further highlighting the danger faced by skiers in an event where they have to race across jumps and around steep turns.

Russia's Maria Komissarova suffered a fractured spine in a training crash last Saturday and had emergency surgery at a hospital built for the Olympics in the most serious injury to an athlete at the Sochi Games.